The HF generator of an ultrasonic bath takes electrical power from the mains voltage source and converts it into a high-frequency power (HF power). This HF power is converted into ultrasonic power, i.e. mechanical power, by piezoelectric oscillating systems. In SONOREX units, PZT oscillating systems (PZT: lead zirconate titanate) are used for this purpose, which have a particularly high efficiency.
The HF generator is fed from the mains via a full-wave rectifier and therefore operates in double half-wave mode. This mains operation mode was chosen for SONOREX ultrasonic baths because it basically represents an optimisation between performance, protection of the cleaning material and noise development. The electrical power of the generator is not constant over time, but is modulated at 100 Hz with sinusoidal mains voltage - see Fig. 1, solid line.
- To improve the effect, the ultrasound is modulated/altered, which in combination with SweepTec depending on the unit, a 4 or 8-fold value of the HF power results as ultrasonic peak power.
- For smaller units with one-way rectification, the maximum value of the ultrasonic peak power Pus is even up to 8 times the effective value of the mains power: Pus = 8 × Peff.
The ultrasonic bath SONOREX SUPER RK 102 H operates in double half-wave mode with an effective value of the mains power Peff of 120 W; the ultrasonic peak power Pus is then 480 W.